【摘要】 在雅鲁藏布江蛇绿岩带的东端罗布莎蛇绿岩的铬铁矿中发现不寻常的硅铁合金组合。 4种硅铁合金的理论分子式分别为Fe0 .84 Si2 .0 0 (Fe3 Si7)、Fe7Si3 、Fe6Si4 以及Fe4 Ti3 Si2 P。这些合金均选自铬铁矿石的人工重砂中 ,在少数颗粒中见到由 3种硅铁合金组成的交生结构 ,明显表明这些合金的同生和同成因性。推测它们为化学反应成因 ,来自于核幔边界地带。更多还原

【Abstract】 Four unusual varieties of Si-Fe alloys occur in ophiolite along the Yarlung Zangbo River. Podiform chromite deposits are distributed in the hurzburgite facies of the Luobusa ophiolite. The Si-Fe alloys are composed chemically of Fe 3Si 7, Fe 7Si 3, Fe 6Si 4, and Fe 4Ti 3Si 2P, and the associated minerals comprising Fe, FeO, SiO 2, Si and Mg silicates occur in chromitite. The intergrowth texture formed by 3 alloys indicate that these alloys have same genesis, and the texture developed in the Si-Fe alloys might be a product of chemical reaction between liquid iron and silicate on the boundary of mantle and core.更多还原